/*
 * Copyright 2011 es-planning Inc.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package jp.arctos.ursus.extension.net;

import java.io.IOException;
import java.net.SocketAddress;
import java.nio.ByteBuffer;
import java.nio.channels.DatagramChannel;
import java.nio.channels.SelectableChannel;

/**
 * Session writer for datagram sessions.
 * 
 */
class DatagramSessionWriter extends AbstractSessionWriter {

    /**
     * {@inheritDoc}
     * 
     */
    @Override
    void doWrite(SelectableChannel selectableChannel, SendRequest request) throws IOException {
        DatagramChannel channel = (DatagramChannel) selectableChannel;
        int written = 0;
        ByteBuffer buffer = request.getBuffer();
        SocketAddress remoteAddress = request.getRemoteAddress();

        do {
            if (remoteAddress == null) {
                written = channel.write(buffer);
            } else {
                written = channel.send(buffer, remoteAddress);
            }
        } while(written > 0 && buffer.hasRemaining());
    }
}
